1. When she smiles, you say, "I like (or use 'love') your charming/magnetic smile." This means, "I admire your attractive smile." It indirectly conveys how beautiful you look when you smile, rather than using a literal translation like, "You are so beautiful when you smile." I hope this helps you!2. When she flashes a smile, you express your appreciation by saying, "I like (or 'love') your enchanting/mesmerizing smile." This conveys the idea that her smile is captivating and enhances her beauty. It's a more natural way of saying "You are so beautiful when you smile" in a less direct manner. I trust this suggestion will be beneficial to you!